Glycogen Storage Disease Type 13: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Glycogen Storage Disease Type 13?
A primary care doctor is often the first doctor a person sees and can order early tests. Because this condition affects muscles, care usually involves a neurologist or a geneticist. A direct primary care or concierge doctor can manage routine care and coordinate with specialists, referring the patient to a neurologist or geneticist when the diagnosis is unclear.
What it is
Glycogen storage disease type 13 is a rare inherited condition. Glycogen is a form of sugar that the body stores in muscles and the liver to use for energy. In this disease, an enzyme called enolase does not work properly. Because enolase does not work, glycogen builds up in the muscles used for movement. That is why the main problems involve muscle tiredness and weakness.
Symptoms
Most people with this condition have trouble exercising. Muscles may feel tired, weak, or painful during activity, and this often improves with rest. Some people have episodes where muscle tissue breaks down after hard exercise, which can cause dark-colored urine.
Causes and who gets it
This disease is passed down through families. A child must receive a changed copy of the ENO3 gene from both parents to have the condition. Parents who carry only one changed copy usually have no symptoms. Because both parents must carry the gene change, the condition is extremely rare.
How doctors diagnose it
Doctors start by asking about symptoms and doing a physical exam. Blood tests can show signs of muscle breakdown, such as high levels of creatine kinase. Genetic testing can confirm the diagnosis.
Treatment
There is no cure for glycogen storage disease type 13. Care focuses on managing symptoms and protecting the muscles. Doctors often suggest avoiding intense exercise, since hard activity can trigger muscle breakdown. Any exercise plan should be made with a doctor, and regular follow-up helps track how the muscles are doing over time.
When to see a doctor
Anyone who has muscle pain, weakness, or dark urine after exercise should talk to a doctor, since dark urine can signal serious muscle breakdown. Children who tire easily or seem weak compared to other children should also be checked.
Common questions
Is glycogen storage disease type 13 life threatening?
Most reported cases involve exercise intolerance and muscle weakness rather than dangerous complications. However, severe muscle breakdown can strain the kidneys. Symptoms like dark urine need medical attention. Each person's situation is different, and a doctor can give guidance based on the individual case.
Can people with this condition exercise?
Many people can do light or moderate activity, but intense exercise often causes symptoms. A doctor can help design a safe activity plan. Rest breaks and stopping when symptoms appear are usually recommended.
Will my children inherit this condition?
A child must inherit a changed gene from both parents to have the disease. If only one parent carries the gene change, the child will not have the condition. The child could still be a carrier. A genetic counselor can help families understand the risks.
How is this different from other glycogen storage diseases?
There are many types of glycogen storage disease, and each one involves a different enzyme. Type 13 is one of the rarest and mainly affects the muscles. Some other types affect the liver more than the muscles.
Sources
- NIH Genetic and Rare Diseases Information Center - Glycogen storage disease due to muscle beta-enolase deficiency
- MedlinePlus - Glycogen storage disease type I: MedlinePlus Genetics
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
